"After reviewing all of the facts surrounding this incident, we firmly stand by our decision and the punishment handed down by the club," Hawke said.

"We're disappointed to learn the NRL does not agree with this punishment and feel they have to come over the top and add a further four weeks and a monetary fine (of $30,000) to the penalty.

"We are perplexed as to why the NRL felt the need to impose further punishment before this process was concluded and it sets an extraordinary precedent to the way matters are handled by clubs in the future.

"In light of this, it appears clubs don't really have a role in imposing penalties on their own employees, so perhaps it's time for the NRL and its integrity unit to decide these matters so that there will be a consistent approach for future offences."

The only way Wighton could play again this year is if the Raiders, who sit three games outside the top eight, make the finals.

If the club's punishment was accepted, Wighton would have been available to play in the round 22 game against Wests Tigers on August 12.

He has already missed Canberra's past two games and the Raiders hoped to count those matches as part of their penalty.

Wighton has five days to appeal the league's sanctions.

NRL chief executive Todd Greenberg had made it clear he didn't agree with the Raiders' stance, warning on Thursday the club could be overruled.

"It's simple as this - I've viewed the footage and I don't think the sanction they've proposed is strong enough," Greenberg said.

Wighton's legal team are attempting to suppress CCTV footage of the February incident, with a decision expected in October on whether it will be made public.

Wighton faces sentencing on November 14 over five charges of assault, including two counts of assault occasioning actual bodily harm and one of public urination.

He changed his plea to guilty in June after initially looking to contest the charges when he first faced ACT Magistrates Court in April.

The maximum penalty for assault occasioning actual bodily harm is five years jail.